package com.sd.repay.utils;

public class HexDump {

    private static final char[] HEX_DIGITS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};

    public static String dumpHexString(byte[] array) {
        return dumpHexString(array, 0, array.length);
    }

    public static String dumpHexString(byte[] array, int offset, int length) {
        StringBuffer result = new StringBuffer();

        byte[] line = new byte[16];
        int lineIndex = 0;

        result.append("\n0x");
        result.append(toHexString(offset));

        for (int i = offset; i < offset + length; ++i) {
            if (lineIndex == 16) {
                result.append(" ");

                for (int j = 0; j < 16; ++j) {
                    if ((line[j] > 32) && (line[j] < 126))
                        result.append(new String(line, j, 1));
                    else
                        result.append(".");

                }

                result.append("\n0x");
                result.append(toHexString(i));
                lineIndex = 0;
            }

            byte b = array[i];
            result.append(" ");
            result.append(HEX_DIGITS[(b >>> 4 & 0xF)]);
            result.append(HEX_DIGITS[(b & 0xF)]);

            line[(lineIndex++)] = b;
        }

        if (lineIndex != 16) {
            int count = (16 - lineIndex) * 3;
            ++count;
            for (int i = 0; i < count; ++i) {
                result.append(" ");
            }

            for (int i = 0; i < lineIndex; ++i)
                if ((line[i] > 32) && (line[i] < 126))
                    result.append(new String(line, i, 1));
                else
                    result.append(".");


        }

        return result.toString();
    }

    public static String toHexString(byte b) {
        return toHexString(toByteArray(b));
    }

    public static String toHexString(byte[] array) {
        return toHexString(array, 0, array.length);
    }

    public static String toHexString(byte[] array, int offset, int length) {
        char[] buf = new char[length * 2];

        int bufIndex = 0;
        for (int i = offset; i < offset + length; ++i) {
            byte b = array[i];
            buf[(bufIndex++)] = HEX_DIGITS[(b >>> 4 & 0xF)];
            buf[(bufIndex++)] = HEX_DIGITS[(b & 0xF)];
        }

        return new String(buf);
    }

    public static String toHexString(int i) {
        return toHexString(toByteArray(i));
    }

    public static byte[] toByteArray(byte b) {
        byte[] array = new byte[1];
        array[0] = b;
        return array;
    }

    public static byte[] toByteArray(int i) {
        byte[] array = new byte[4];

        array[3] = (byte) (i & 0xFF);
        array[2] = (byte) (i >> 8 & 0xFF);
        array[1] = (byte) (i >> 16 & 0xFF);
        array[0] = (byte) (i >> 24 & 0xFF);

        return array;
    }

    private static int toByte(char c) {
        if ((c >= '0') && (c <= '9'))
            return (c - '0');
        if ((c >= 'A') && (c <= 'F'))
            return (c - 'A' + 10);
        if ((c >= 'a') && (c <= 'f'))
            return (c - 'a' + 10);

        throw new IllegalArgumentException("Invalid hex char '" + c + "'");
    }

    public static byte[] toByteArray(String hexString) {
        return hexStringToByteArray(hexString);
    }

    public static byte[] hexStringToByteArray(String hexString) {
        int length = hexString.length();
        byte[] buffer = new byte[length / 2];

        for (int i = 0; i < length; i += 2) {
            buffer[(i / 2)] = (byte) (toByte(hexString.charAt(i)) << 4 | toByte(hexString.charAt(i + 1)));
        }

        return buffer;
    }


}
